Set zookeeper host and port for spring-cloud-bus

Question

I have a project with spring-cloud-starter-bus-kafka and I set the kafka URL inside application.yml like so:

spring.kafka.bootstrap-servers=localhost:9092

This works find when kafka and zookeeper are deployed locally, but if I move kafka and zookeeper to their own servers I get an error when spring-boot starts:

New config

spring.kafka.bootstrap-servers=192.168.0.120:9092

Error

{
    "@timestamp" : "2018-05-15T14:56:45.628+00:00",
    "message" : "Opening socket connection to server localhost/127.0.0.1:2181. Will not attempt to authenticate using SASL (unknown error)",
    "logger_name" : "org.apache.zookeeper.ClientCnxn",
    "thread_name" : "main-SendThread(localhost:2181)",
    "level" : "INFO"
}
{
    "@timestamp" : "2018-05-15T14:56:45.629+00:00",
    "message" : "Session 0x0 for server null, unexpected error, closing socket connection and attempting reconnect",
    "logger_name" : "org.apache.zookeeper.ClientCnxn",
    "thread_name" : "main-SendThread(localhost:2181)",
    "level" : "WARN",
    "stack_trace" : "java.net.ConnectException: Connection refused
        at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
        at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717)
        at org.apache.zookeeper.ClientCnxnSocketNIO.doTransport(ClientCnxnSocketNIO.java:361)
        at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1141)"
}

How I should config kafka and zookeeper to connect to their servers?

Answer 1

There's a section on Spring's documentation about it:

https://docs.spring.io/spring-cloud-stream/docs/Ditmars.SR3/reference/htmlsingle/index.html#_kafka_binder_properties

You can replace the default URL on Application.yml

spring:
  cloud:
    stream:
      kafka:
        binder:
          zkNodes: ADDRESS:PORT
          brokers: ADDRESS:PORT

Or using .properties

spring.cloud.stream.kafka.binder.zkNodes = ADDRESS:PORT

Answer 2

What version are you using? With 2.0, no connection to zookeeper is required.

With earlier versions, you need to set spring.cloud.stream.kafka.binder.zkNodes.

Spring Cloud Stream documentation here.